Javascript function for validating email address

I've coded a working form, all checks are great but for some reason the hardest part is trying to stop form submission before validation.

Other form values are available using a similar syntax, although this becomes more complicated if you're using SELECT lists, checkboxes or radio buttons (see below for examples). All you need to do is extend the command is encountered, execution of the function is halted.There are two main methods for validating forms: (usually done using Java Script).Server-side validation is more secure but often more tricky to code, whereas client-side (Java Script) validation is easier to do and quicker too (the browser doesn't have to connect to the server to validate the form, so the user finds out instantly if they've missed out that required field! In this tutorial we'll build a simple form with client-side Java Script validation.In other words if the first condition fails, the second condition will not be tested and so forth.Only when all conditions have been satisfied do we reach the command, in which case the form will be submitted.

I tested your first piece of code on a form and it does not work at all.